Just had my super pastel male out looking at him and looked at his belly button. He seems to have a tiny bit of dried umbilicus still stuck to him. He has been eating, pooping, peeing, acting fine. He is a 166 grams and his sister, who is about 140g, has no umbilicus at all left.

Is this something to be worried about? Will it fall off on its own? Any easy ways to get it off?
Maybe I'm worrying too much but I'm just watching out for my little guy.